Monotouch - make UIView scrollable - xamarin.ios

I have a view with 4 text boxes and and a logo at the top - when the user is entering information the text pad covers up some of these controls, how can I make the view scroll so that this isn't an issue.
I have tried adding the view to a UIScrollView but that doesn't seem to do anything?

I've included a snippit below of how I've handled your situation. If I'm understanding you correctly, you do not wish to have a scrollable view, rather you want to the view to move in conjunction with switching to and from fields to alleviate and visual hindrances caused by the keyboard.
Goodluck!
private void ScrollTheView(bool movedUp, float scrollamount, UIView ViewToMove)
{
//To invoke a views built-in animation behaviour,
//you create an animation block and
//set the duration of the move...
//Set the display scroll animation and duration...
UIView.BeginAnimations(string.Empty, System.IntPtr.Zero);
UIView.SetAnimationDuration(0.15);
//Get Display size...
RectangleF frame = ViewToMove.Frame;
if (movedUp) {
//If the view should be moved up,
//subtract the keyboard height from the display...
frame.Y -= scrollamount;
}
else {
//If the view shouldn't be moved up, restore it
//by adding the keyboard height back to the original...
frame.Y += scrollamount;
}
//Assign the new frame to the view...
ViewToMove.Frame = frame;
//Tell the view that your all done with setting
//the animation parameters, and it should
//start the animation...
UIView.CommitAnimations();
}

You need to set more to the UIScrollView than just put subviews in it. Set up the ContentSize property properly for the complete size of the subviews so the scrollview knows about the larger content in it, than you can control the scrolling position, zoom factor and so on.
There are plenty of samples on iOS SDK, just check the UIScrollView documentation, transformation to Monotouch from ObjectiveC is straightforward or check blog post at http://blog.touch4apps.com/home/iphone-monotouch-development/monotouch-infinite-loop-image-scroll-view where I have a sample with images autoscrolled in UIScrollView.

something like this.
textBox.EditingDidBegin += delegate {
var offset = scrollView.contentOffset;
offset.Y -= 200;
scrollView.contentOffset = offset;
}

Related

Android: Custom bottom sheet dialog

How can I implement following design functionality with android standard component bottom sheet:
Image when Bottom sheet dialog fragment will appear:
Image when user scrolled to up to view bottom of content:
I will use ViewPager to scrolling header images and RecyclerView to showing descriptions and other informations. And parallax effect to ImageView(which are placed in ViewPager) when scrolling content vertically. Have a minimum height of the ImageView(and ViewPager), user can't collapse fully it (Look to second screenshot, which is user scrolled until the end of content).
I want stop scrolling ImageView when it will reach to minimum height(look to second one Screenshot), but the content of below ImageView should be continue scrolling
This can be done with an if statement in an on scroll view such as shown below:
ScrollView scrollView = findViewById(R.id.scrollView); //Adjust for your code
ImageView imageView = findViewById(R.id.imageView); //Adjust for your code
boolean imageIsHidden = false;
int threshold = 250;
scrollView.getViewTreeObserver().addOnScrollChangedListener(new OnScrollChangedListener() {
#Override
public void onScrollChanged() {
int scrollY = rootScrollView.getScrollY();
if(scrollY >= threshold){
imageIsHidden = true;
//Move image outside of scroll view so it doesn't scroll
}
else if(scrollY < threshold && imageIsHidden){
imageIsHidden = false;
//Move image inside of scroll view so it does scroll
}
}
});
What this does is has a boolean called imageIsHidden and an integer called threshold. Threshold is where you want it to make it disappear. You will need to play around with this value to find a sweet spot.
You will also need to implement moving the image inside and outside of the scroll view as well in the if and if else statement.

Adding nested stackviews programmatically using xamarin.ios c#

I am creating a app for both android and ios using xamarin and mvvmcross.
In the ios app I want to add outer vertical stackview having nested horizontal stackviews. Basically I just want to create a basic person details screen where will be Label on left and textfield on right which will go in one horizontal stackview and like this there will many horizontal stackviews nested in outer vertical stackview.
I am looking for such example on internet but seems most of the examples are in swift but I was hardly able to find some in c#.
Can someone please help.
Thanks,
Santosh
UIStackView leverages the power of Auto Layout and Size Classes to manage a stack of subviews, either horizontally or vertically, which dynamically responds to the orientation and screen size of the iOS device. You can learn about it through this documentation.
In your case, we can construct a vertical stack to place several horizontal stack:
UIStackView verticalStack = new UIStackView();
View.AddSubview(verticalStack);
verticalStack.Axis = UILayoutConstraintAxis.Vertical;
verticalStack.TranslatesAutoresizingMaskIntoConstraints = false;
// Use auto layout to embed this super vertical stack in the View. Also there's no need to set the height constraint, vertical stack will automatically adjust that depending on its content
verticalStack.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor).Active = true;
verticalStack.TopAnchor.ConstraintEqualTo(TopLayoutGuide.GetBottomAnchor()).Active = true;
verticalStack.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor).Active = true;
for (int i=0; i<10; i++)
{
// Here try to put some horizontal stack with Label on left and textfield on right in the father stack.
UIStackView horizontalStack = new UIStackView();
horizontalStack.Distribution = UIStackViewDistribution.EqualSpacing;
horizontalStack.Axis = UILayoutConstraintAxis.Horizontal;
// UIStackView should use AddArrangedSubview() to add subviews.
verticalStack.AddArrangedSubview(horizontalStack);
UILabel textLabel = new UILabel();
textLabel.Text = "text";
UITextField textField = new UITextField();
textField.Placeholder = "enter text";
horizontalStack.AddArrangedSubview(textLabel);
horizontalStack.AddArrangedSubview(textField);
}
But if every horizontal stack's subViews are almost the same style and layouts. Why not try to use UITableView? You just need to set the single cell's contents and layouts, then use it in the tableView. Moreover this control is reused and scrollable.

How to adjust size of UITextView automatically ?

I want to make speech bubbles but there is a problem adjusting size of the bubbles in UITextView.
is there a way to increase the size of the Textview automatically depending on the length of the
text by using UITextView?
Okay I found a better way of doing what I was suggesting. Rather then deal with the UIView and resizing depending on the text inside it. I just made the UITextView have a rounded edge which now looks like a panel. Perfect. Hope this helps someone!
If your interested in the code
- (void)drawRect:(CGRect)rect
{
CGRect frame = self.frame;
frame.size.height = self.contentSize.height;
self.frame = frame; // Drawing code
self.clipsToBounds = YES;
self.layer.cornerRadius = 10.0f;
}
I think I understand what your getting at. I had this problem the other day. This bit of code will adjust the UITextView contents. Create a new class and call this into it via a new class. If you want to adjust the View well I'm still working on that :-P
Hope this helps
- (void)drawRect:(CGRect)rect
{
CGRect frame = self.frame;
frame.size.height = self.contentSize.height;
self.frame = frame; // Drawing code
}

How do I dock a UserControl into a FlowLayoutPanel?

I have a FlowLayoutPanel and a UserControl.
I've added multiple usercontrols into the FlowLayoutPanel, and I'm trying to dock them to the top, so when I change the size of the FlowLayoutPanel the size (width) of the usercontrols changes accordingly.
You cannot dock anything inside a FlowLayoutPanel, it's simply ignored.
Check out the answer here apparently posted by the Microsoft team.
They say:
The FlowLayoutPanel relies on a largest control to effectively define the column/row within it. The code below set's the size of the first control to the width of the FLP to achieve a layout similar to what you want.
private void flowLayoutPanel1_Layout(object sender, LayoutEventArgs e)
{
flowLayoutPanel1.Controls[0].Dock = DockStyle.None;
for (int i = 1; i < flowLayoutPanel1.Controls.Count; i++)
{
flowLayoutPanel1.Controls[i].Dock = DockStyle.Top;
}
flowLayoutPanel1.Controls[0].Width = flowLayoutPanel1.DisplayRectangle.Width - flowLayoutPanel1.Controls[0].Margin.Horizontal;
}
Key thing is to use the Layout event.
This solution worked for me up to a point. Your UserControls have to have AutoSize turned off / stay a uniform size.
In my case I wanted AutoSize turned on so as to allow the UserControl to expand/contract vertically while filling the width of the FlowLayoutPanel.
I had to find a different solution. But the above might help you in your case.

MonoTouch: How to resize a view.Frame inside Draw override and draw correctly?

the problem I am having it that if inside the UIView Draw override, I change the view frame size, drawing a rectangle is not working as expected.
If I change the view frame size outside of the Draw override, it works fine. Is this an expected behavior or is it a problem with monotouch only?
This is the code I am using:
class ChildView : UIView
{
public override void Draw (RectangleF rect)
{
base.Draw (rect);
CGContext g = UIGraphics.GetCurrentContext();
//adding 30 points to view height
RectangleF rec = new RectangleF(this.Frame.Location,this.Frame.Size);
rec.Height+=30;
RectangleF rec_bounds = new RectangleF(0,0,rec.Width,rec.Height);
this.Frame=rec;
this.Bounds=rec_bounds;
//drawing a red rectangle to the first half of view height
UIColor.Red.SetFill();
RectangleF _rect = new RectangleF(this.Bounds.Location,this.Bounds.Size);
_rect.Height=_rect.Height/2;
g.FillRect(_rect);
}
}
However, the output of this code is this: (it should draw only 30 points red, but it draws 60 points)
Here is a link to download the project to reproduce this issue:
www.grbytes.com\downloads\RectangleDrawProblem.rar
Καλημέρα!
This behavior is expected. If you want to change the view's frame inside the Draw override, do it before getting the current context. That is because the graphics context also has a size and that is the size of the view at the time you are retrieving it.
Also, there is no need to set both the Bounds and the Frame of the view. You can just set either of them in this case.
By the way, I don't think you need to call base.Draw(). According to the Apple documentation, "If you subclass UIView directly, your implementation of this method does not need to call super."

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